"Flowing Into the Future," Feature Article, February 2004

flowing into the future

Where does virtual reality meet CAD, CFD, and FEA? In a futuristic technology poised to accelerate mechanical engineering.

by Jean Thilmany,
Associate Editor

Remember those white, paper glasses, a blue piece of cellophane as one lens, a red piece for the other? They were intended to give the perception of depth to the limited number of three-dimensional movies out there. Apart from that, however, they were a 1950s fashion statement.

Fashions change. There hasn't been a 3-D movie released in years, but it's time for the technology behind the movies to make a comeback.

The problem with 3-D movies, as Mark Bryden sees it, was that moviegoers couldn't make on-screen changes as they watched the film. But tampering with movies isn't his aim. Bryden, a university researcher, and his colleagues say the technology they're developing will let engineers design as they analyze in three dimensions in the not-too-distant future.

Bryden, an assistant professor of mechanical engineering at Iowa State University in Ames, is part of a team that wants to revolutionize virtual-reality software for engineers by incorporating computational fluid dynamics and finite element analysis into the virtual-reality mix. He works in a growing field of technology called virtual engineering. Its purveyors hope that one day engineers can design in real time, make changes in real time, and see those changes immediately reflected in the virtual model.

"We work on issues that are technically very challenging," he added. "You have to think of: 'Where do I want to be in 10 years?' We have to think 10 years down the line in order to move forward."

Iowa State researchers are working on technology to let engineers design and analyze in real time surrounded by three-dimensional virtual reality.

One of the best parts about what Bryden calls virtual engineering will be its marriage of analytical capabilities. Engineers can perform finite element or CFD analysis—or a combination of the two—and see the solution immediately. Results won't be described in a list of numbers; they'll be visible. After running a CFD problem, the engineers will see—and maybe one day feel—air flowing around a vehicle, for instance. They could then tweak, say, a piece of the auto body to see how the change affects airflow.

"Those types of calculations are very challenging," Bryden said. "If you're doing a CFD calculation now, it can take from 10 minutes to three weeks. We're asking ourselves: 'Can I make this calculation faster? And how can I make it faster?' "

Bryden's work in pushing CFD farther into the realm of the nonspecialist user is significant because not so long ago high-end analyses like FEA and even CFD were the exclusive domain of highly trained analysts. CFD was introduced in the 1960s, but wasn't sold widely by software vendors until the 1980s. FEA became available to mainstream engineering users slightly before CFD.

Only relatively recently have some companies in the computer-aided design and computer-aided engineering markets started working to bring analysis capabilities closer to the early stages of product design, almost always carried out in a CAD package, said Vincent Harrand, director of software technology at software developer CFD Research Corp. of Huntsville, Ala. Now Bryden and his team want to extend the capabilities of CFD, FEA, and visualization even farther. Much farther, in fact.

The goal for virtual engineering—when it is eventually realized—is for the engineer to better focus on solving the problem at hand, without spending undue amounts of time gathering information, modeling the information, and then analyzing it, Bryden said. In the future, all aspects of product design, manufacture, and repair will be done virtually, before the product is manufactured.

Heat From a Virtual Turbine

For example, power plant engineers currently conduct burner studies and run nitrogen-oxide-reduction analyses to decide how the plant would operate best. All that analysis is time-consuming, and the results aren't easily understood unless you're well-versed in analysis, Bryden said.

When it comes time for engineers to share details of their studies with others, they frequently develop two-
dimensional pictures and animate their results to help make the information easily digestible, he added. But those methods have unfortunate side effects. Analysts often focus on the information they think will be of highest interest to plant engineers. In doing so, they risk overlooking information outside their realm of experience, although it might be pertinent to plant operation.

In other words, from a complex array of information available for computational analysis only a portion will be analyzed and shared, Bryden said. And when humans make decisions on which information to tease out from an overwhelming amount, they tend to focus on the areas of information they're interested in or that they know about; the rest gets overlooked. It's human nature.

Bryden and his team use open-source, extensible software that lets users link many types of data within what's called a computer-automatic virtual environment, or CAVE, or in another virtual-reality device. Iowa State University, where Bryden teaches, is home to the C6, a six-sided immersion device designed to make viewers feel as if they're completely surrounded in a virtual environment.

The virtual engineering system would integrate CFD and FEA modeling and simulation technologies so engineers would feel as though they're walking through a system, like a power plant, testing as they go.

"You would stick your head in the furnace to see what's happening in there with combustion," Bryden said. "You'd walk on and see what's happening in the turbine—how the air is moving. Then, at the end of your walk, you'd put all that together to have an overall picture of the plant.

"Although many excellent engineering analysis techniques have been developed, they're not routinely used as a part of engineering design, operations, control, and maintenance," Bryden said. "The time required to set up, compute, understand the result, and then repeat the process until an adequate result is obtained exceeds the time available."

Today, engineers who use linked CFD and CAD technology might make a model of a turbine, and then modify airflow or the design to see how the changes affect operation. But analysis results take a while to generate, Bryden said. That's a problem. An engineer generally leaves the model alone for a time while the software runs the problem. That can lead to a lot of forced breaks for coffee. In a virtual engineering system, results would happen right away. And they'd mirror how results would look in the real world.

Eventually, engineers could make changes in one part of the plant, or within one system, and see the effects immediately reflected throughout the plant.

"You'd change the coal nozzle to see how that changes what's happening within the steam turbine," he said. "You could modify the nozzle and see how that affects the entire system. We do lots and lots with graphics. When it's complex, you really need to see it in 3-D, and you need a way to interact with it."

Bryden summarizes his work as the capability to permit the coupling of multiple high-fidelity models, like CFD and FEA, linked with graphical representations, detailed models, and other information in order to create virtual power plants and other virtual engineering systems.

Using virtual engineering software, engineers will one day see, and maybe even feel, air flowing around a virtual vehicle during analysis long before a prototype needs to be built.

The software he and his team have built to power a virtual engineering system can read, display, and visually couple many types of data, including CFD, CAD, and FEA in either two dimensions or in 3-D. It's called VE-Suite. The challenge of building a complete virtual engineering environment, Bryden said, comes in coupling software packages as well as in the limitations of visualization and computing hardware today.

Bryden's hope is that automakers will one day use this linked visualization, analysis, and design technology to help design and test fluid and thermal systems.

That's no surprise to Howard Crabb, widely credited with being one of the founding fathers of CAD technology, which he helped create as a researcher at General Motors Corp. in the early 1960s. He served as a technology visionary for many years at GM and at Ford Motor Co., and is now president of the consulting firm Interactive Computer Engineering in Grosse Pointe Woods, Mich.

Crabb predicts that virtual engineering—which he defines as the capability to put virtual reality inside an engineer—will become cost effective within the decade. He's the author of The Virtual Engineer, a book that defines how companies can use the powerful supercomputing capabilities available today to streamline business practices.

While he talks about putting virtual reality inside an engineer, Crabb doesn't mean it literally, of course. He's speaking about using the technology in much the same way Bryden proposes. Engineers would be surrounded by a virtual part or, more likely, by an entire vehicle or assembly that appears before them as it would in real life. They would then see how the parts are interrelated and could make changes by merely touching or tweaking a part. The change they made to one part of the assembly would immediately affect the rest of the system, and an engineer would see that.

The new method aims to continue a long line of recent engineering technology pushes to bring analysis on board as soon as possible in the design cycle, says one of Crabb's colleagues.

"Once, modeling and analysis occurred late in the product development process, usually after the design was documented on a CAD system, and then, only analysts, not design engineers, were empowered to use the tools," Larry McArthur, cofounder of the National Center for Manufacturing Sciences, writes in the forward to The Virtual Engineer. "Today, that would lead to extinction. It was the early 1980s that Ford began changing the process, first moving solids modeling and analyses to the beginning, and then empowering design engineers with these new tools."

The enormous increase in computing speed coupled with the deep drop in computer prices over the past generation have pushed engineering capabilities beyond anything that an engineer in the 1950s, drawing with pen on paper, could have imagined, Crabb said. While computing power will make virtual engineering possible, it also means that the engineering emphasis will be on designing the total product as a system, rather than on individually designing the pieces that make up the product.

It will also allow CFD, CAD, and FEA to be tightly integrated in all future technologies. Advanced computing speed will help virtual engineering expand and become cost effective, just in time to house the exploding amount of information available about a product, Crabb maintains.

"Just as faster computers will allow engineers to perform design simulations quicker, companies will also be able to store knowledge about the product and why it was designed in a particular way," Crabb said.

He expects such technologies to be particularly useful to large manufacturers, like automakers, that quickly produce complex vehicles made up of many disparate parts, each of which needs to meet safety standards. Industry engineers would readily use the CAD, FEA, and CFD programs to analyze thermal and fluid systems.

Looking at the Numbers

Central to Bryden's work with virtual engineering is the capability to visualize CFD problems. That means a CFD analysis of a steam turbine will look to engineers like a steam turbine, not like a series of graphs and numbers.

Bryden and his team use CFD visualization software from Acuitiv Software of Batavia, Ill.; from Computational Engineering International of Apex, N.C., and from Intelligent Light of Lyndhurst, N.J. Products from these companies allow CFD problems to appear as actual representations of objects, so engineers will get a more intuitive understanding of how fluid flows.

Bill Panepinto, general manager of Acuitiv, expects CFD software coupled with visualization software to be commonly used in CAVE environments in the future. CFD analysis is already showing up in unlikely places, and the coupling of that technology with virtual engineering will only make CFD more prevalent, he said.

For instance, a maker of canned potato chips is using CFD to determine how best to stack the chips inside the cans, Panepinto said.

"Folks are using CFD for differentiation from their competitors and to find problems early," he said. "In the automotive industry, they're using CFD in the prototyping phase. With our software, they can bring the product up in a CAVE and build a virtual prototype and work out the bugs virtually. It would cost about $200,000 and 10 weeks to build a fiberglass prototype."

That's the kind of cost savings that have folks like Bryden and Panepinto working on cutting edge engineering technologies that promise to once again revolutionize the way engineers design and analyze.